By Chris Rea,
Managing Director AES Engineering and AESSEAL
Many environmentally aware businesses are investing in Electric Vehicles, but with valid concerns about cost, range and availability of charging, some vehicle manufacturers continue to favour a future based around hydrogen.
The futuristic-looking vehicle in the picture is a Toyota concept car from 2019 and as of 2024, there are a number of hydrogen fuel cell cars on the road. The Toyota Mirai and the Hyundai Nexo offer a range of around 400 miles but there are only a dozen or so hydrogen fuel stations in the UK and sightings on the road are extremely rare.
BMW also has a fuel cell version of the iX5, which it is currently testing on the grounds that “one technology on its own will not be enough to enable climate-neutral mobility worldwide.” Oliver Zipse, Chairman of BMW AG maintains: “Hydrogen is the missing piece in the jigsaw when it comes to emission-free mobility.”
The AES Engineering Ltd Group, with our global headquarters at AESSEAL’s Factory for the Future in Rotherham, has invested in the current generation of EVs for pool cars and vans as part of our 29x29 commitment to spend £29 million ($40 million) by 2029 on environmental investments.
We also support the Betterworld Solutions project, which aims to share environmental best practice in industry. Naturally we are interested in all alternatives that can contribute to a net zero future.
On the face of it, hydrogen seems like a good candidate. It can be burned cleanly as fuel or used in a fuel cell where the hydrogen reacts with oxygen – usually in the presence of an expensive platinum catalyst - to produce electrons that charge a battery.
The problem is that while hydrogen is the most plentiful element in the universe, it isn’t available for free. At present is you want hydrogen there are three main colour-coded sources to choose from.
‘Grey hydrogen’ is extracted from natural gas releasing CO2 emissions into the air. If the CO2 emissions are trapped and stored permanently underground, this produces what is termed ‘blue hydrogen’. The most environmentally-friendly variant is produced by hydrogen extracted from water via electrolysis, using renewable electricity, and is called ‘green hydrogen’.
A report to the World Economic Forum on hydrogen fuel does a good job in explaining how we arrive at the various colour variations of hydrogen (https://www.weforum.org/agenda/2021/07/clean-energy-green-hydrogen/).
Its conclusion: “Green hydrogen is the only type produced in a climate-neutral manner, meaning it could play a vital role in global efforts to reduce emissions to net zero by 2050.”
In addition to green hydrogen, there is the possibility of finding sources of ‘white hydrogen’, which is naturally occurring pure hydrogen. Small deposits have been found by accident but so far there are no commercial scale discoveries.
The apparent promise of hydrogen as an asset in the drive to net zero encouraged South Yorkshire Invest to promote the region as a low carbon hub, with ‘green hydrogen’ at the heart.
ITM runs a 1-gigawatt PEM electrolyser manufacturing plant in Sheffield and has one of the few UK public access hydrogen refuelling stations at the Advanced Manufacturing Park, funded by InnovateUK, just off the M1, Junction 33. However, demand for hydrogen has not risen as the company predicted. Plans for a second UK ‘gigafactory’ were put on hold last year, while the company goes through restructuring.
The problems with hydrogen are two-fold. Lack of current readily available supplies (few filling stations) and the fact that even ‘green hydrogen’ faces challenges on environmental grounds. This is because every transformation of energy involves wasted heat.
David Cebon, professor of mechanical engineering at the University of Cambridge, giving evidence to the UK House of Commons Science, Innovation and Technology Committee, pointed out that it takes around three times more electricity to make the hydrogen to power a car than it does to charge a battery.
Asked by the committee chair, Greg Clark, if this inefficiency problem could be mitigated by using unneeded generation capacity from wind turbines at times of low demand, Prof. Cebon said the scale of energy required was enormous, and the inefficiency of the energy transformation was a huge disadvantage.
“The little bit of extra (left over on a windy day) is by no means sufficient to make the hydrogen that is needed for the proposed uses of running heavy goods vehicles or heating buildings, which require absolutely massive amounts of electricity,” he said.
There are certainly possible use cases where having a clean combustion engine could have considerable advantages – in aviation for example. However, the lower fuel density of hydrogen compared with kerosene may mean serious range limitations compared with the current generation of aircraft. For cars and trucks, hydrogen offers quick refuelling, higher payloads and longer range than the current battery technologies.
Outside of transportation, proposed UK government-backed trials on using hydrogen to heat homes in Redcar and Whitby have been cancelled due to a combination of lack of feedstock and opposition from consumers due to perceived safety risks. The government says it will review the results of a hydrogen heating trial in Fife, as well as others in Europe, before making a final decision on the fuel’s role in domestic heating.
While hydrogen continues to be much discussed and may come into its own in certain use cases – e.g. fertiliser production - for mass transportation it looks as if batteries are going to have the edge for the foreseeable future.
Huge investment is being put into the next generation of lighter, cheaper, longer-range all solid state batteries with manufacturers like Nissan hoping to bring these to the market as early as 2028.
If these batteries fulfil their promise, it looks like all the colours of the rainbow of hydrogen are doomed to take, at best, second place.
Photo by Darren Halstead on Unsplash
